Molded black powder explosive



MOLDED BLACK POWDER EXPLOSIVE Filed April 23, 1931 June 6, 1933. I J. E. SLUSSER 1,913,344

Patented June 6, 1933 OFFICE JAMES ErS LUSSER, OF PITTSTON, PENNSYLVANIA,

ASSIGNOR, BY MESNE ASSIGNMENTS,

TO ATLAS POWDER COMPANY, A CORPORATION OF .DELAWARE MOLDED BLACK POWDER EXPLOSIVE Application filed April 23,

This invention relates to improvements in molded black powder explosives, and in the methods of manufacturing said explosives.

One object of my invention is to provide an explosive of the stated character suitable for blasting and other purposes for which black powder is adapted, having generally improved characteristics as hereinafter set forth.

Another object of my invention is to provide a method of manufacturing an explosive of the. character set forth, affording a material economy in the cost of production.

Still another object of the invention is to provide a method of manufacturing molded black powder explosives which shall reduce the hazards of manufacture.

The invention further resides in certain novel process and structural details, as hereinafter set forth and illustrated in the attached drawing, in which:

Figure 1 is a view in perspective illustrating a step in the manufacture of the blasting powder in accordance with my invention;

Fig. 2 is a sectional perspective view illustrating a further step in the process;

Fig. 3 is a view in perspective of the product in an intermediate stage;

Fig. 4 is a view in perspective of the finished product; and

Fig. 5 is a fragmentary perspective illustrating a structural detail of the product.

Heretofore, molded black powder of a 36 character suitable for blasting has been produced in'the form of cylindrical pellets about 2" long and 1%" in diameter, although sizes both larger and smaller have been used, each pellet having a central longitudinal opening 40 extending from one end to the other. These pellets were formed in a pellet press by simple compression of the ingredients in suitable molds or dies, said ingredients generally consisting of a mixture of granules of the powder with a certain proportion of powder dust or fines. This mixture was introduced into the molds in a moist or semi-moist condition, and application of pressure resulted in the production of the pellet which after air drying was hard and of the stated form. Fol- 1931. Serial No, 532,341.

lowing production of the pellets as described,

it has been the practice to wrap a number of the pellets end to end in a suitable envelope which was thereafter water and air-proofe by dipping in paraflin wax. The end prodnot consisted of a cylindrical stick, or cartridge, approximately 8 long and of the diameter of the pellets.

Cartridges thus produced have not been altogether satisfactory from either the standpoint of production or use. Production costs, for example, were relatively high by reason of the requirement for expensive presses and the cost of maintaining and operating them. Furthermore, in this process of manufacture it was found impracticable to use power only in the finely divided or wheel-cake stage by reason of the practical impossibility of properly regulating the density of the pellet and by reason further of the difiiculty of feeding the fine powder in the machines. This entailed the production in the preparatory stages of the process of a granulated black powder which not only increased the total cost of production, but also materially increased the hazards of manufacture already great by reason of the use of the pellet presses. Even employing a granulated powder base, or a mixture of granules and fines, there has been a tendency in the prior product toward lack of proper and uniform density. The limitations of the pellet presses have also contributed undesirable features. Pellets pro-- duced in these presses were necessaril of small diameter and short length, since only 1n the smaller sizes could anything approaching uniform density be obtained. Also, the cost of presses capable of producing largerpellets was prohibitively high. The consequent necessity of forming cartridges of a 90 suitable length by uniting several of the relatively small pellets in a superimposed wrap per, introduced an undesirable rapid come bustion characteristic in the finished product, due to the ability of the combustion to progress between the pellet joints and between the pellets and the wrapper; and the wrapping operation itself involveda substantial expense.

In producing the explosive in accordance 10c vper 8, see

with my invention, I preferably first form a =cylihdrical open-ended envelope 1 of paper or other suitable material, this envelope being somewhat greater in length than the desired length of the finished blasting stick. Preferably, I employ an envelope consisting of an inner layer 2, see Fig. 5, of unfinished and water-absorbent paper and an outer layer 3 of water-proofed paper, the latter being rendered water-proof bymeans reducing to a minimum incorporation in the paper of any product, such as parafiin wax, rosin, bitumen compounds, etc. which might have the effect when the stick is exploded of producing noxious gases as a product of combustion.

An envelope so formed is mounted on end, as shown in Fig. 1, upon asuitable support 4 having a cylindrical projection 5 dimensioned so neatly fit within the end of the envelope. The projection 5, the length of which is determined as hereinafter made clear, may be provided with a central recess 6 adapted for reception of the end of a cylindrical rod 7 which will extend longitudinally and centrally of the envelope 1 as illustrated. In the upper end of the envelope 1, I insert the lower cylindrical end of a funnel-shaped hop- Fig. 2, and in addition provide a cylindrical plunger 9 having an axial passage for the rod 7, the rod thereby acting as a guide for the plunger. The plunger which is only slightly less in diameter than the envelope 1 is adapted to fit neatly within the lower cylindrical end of the hopper 8 which fits within the envelope as illustrated. Anyv suitable means such as a hollow plunger eX- tension or rod 11 may be provided for vertically reciprocating the plunger 9 upon the guide rod 7 and within the hopper 8. When the plunger is elevated to a position corresponding to that shown in Fig. 2, powder in the hopper is permitted to pass to the envelope, and when subsequently the plunger is depressed, this powder is compacted within the envelope. When the plunger 9 has entered the lower cylindrical and of the hopper 8, further passage of the powder from the hopper to the envelope is prevented, so that the amount previously passed into the envelope ma 1 be thoroughly compacted by tamping with the plunger before admission of any further quantity of the powder. Ob-

viously, the passage of powder from the hopper to the envelope may be accurately controlled by movement of the lunger 9, and in the process of formation, the powder is admitted in small quantities only, vidual portion being thoroughly compacted in the envelope by reciprocatory action of the plunger 9. 7

When the envelope has received the required amount of powder and the'latter has been thoroughly compacted and tamped, the hopper 8, the plunger and the rod 7 are withdrawn and the envelope subsequently reeach indimoved from the projection 5 of the base 4. The envelope and contained powder are thereafter placed in a suitable drier, the ends of the envelope being left open, and subjected to a drying operation which removes as much as desired of the moisture content of the powder and leaves the latter in hard and solid condition within the envelope. Thereafter the extended ends of the envelope are folded over as illustrated in Fig. 4 and secured in position and the ends sealed either by mechanical means or by means of glue or other adhesive material. The use of an inner moisture-absorbent surface in the envelope 1, as shown in Fig. 5, has been found to facilitate the drying operation, moisture being absorbed from the powder by the inner envelope and beingsubsequently removed from the latter in the normal process of dry ing.

In conducting the process as outlined above, I have found it practicable to employ black powder in the wheel cake stage of manufacture, and am able with this material to form in one piece a cylindrical stick of substantially any desired length and diameter which shall be substantially of uniform density throughout. cake powder may be employed where the normal moisture content is relatively high, it is preferred to add duction into the envelope an additional amount of moisture, and I have found that the hardness of the finished product may be controlled to some extent by the amount of moisture in the powder during the tamping operation. This is due to the cementing action of the water soluble ingredients of the powder which in more or less amount are dis solved by tallize when the water is evaporated. In general, it is undesirable to have less than 1% moisture content, since lesser amounts tend to produce a stick having insufficient hardness and strength. However, there are to be no limitations in this respect, since for certain purposes exceptional hardness and resistance to fracture are not essential. I have found that the physical properties of the finished product may also be varied to some extent by the tamping force applied through the plunger 9, a greater tamping force resulting in a more compact and denser and harder product. Obviously, the process is not dependent upon any exact formula for the black powder.

My invention over the prior methods of manufacturing explosives of this type. The method, for example, works a material economy in the production of the blasting powder over the prior practices. The apparatus required for my process is extremely simple and inexpensive both as to original and maintenance costs and the cost of operation, and the relatively the water to subsequently recrys-.

affords material advantages While normal wheel .9 to the powder before introexpensive pellet machines used in the prior methods are eliminated. The process further eliminates the necessity for a separate wrapping operation subsequent to the formation of the pellets as required in the prior practice, since by my process the pellet is formed directly in the envelo e.

' In addition to the ibregoing economies, a further substantial saving is realized by the ability to employ black powder in the wheel cake sta e and the elimination of granular powder roin the process. In the prior methods, the requirement for use of the granular powder, as set forth above, necessitated several additional operations in the production of the granules, namely, the compressing of the wheel cake powder into a press cake and subsequent coming of the press cake to form the granules. My process as compared with the prior processes employing pellet presses effects a substantial economy of production.

In addition to the advantage of economy, my process has materially reduced the hazards of manufacturing this class of explosive. The relatively hazardous operations of pressing and granulating the black powder in the preparatory process is eliminated, as well as the pellet press operation which is one involving a considerable danger. The process makes possible production of cartridges of relatively low density having the hardness and mechanical strength required for commercial usage. Heretofore the lowest density found practicable in commercial black powder cartridges of the type involved-as expressed in terms of cartridge-count was 214 of the standard 1% x 8" cartridges for 100 lbs. of explosive. Even this density involved manufacturing difiioulties of magnitude, and the product was lacking insturdiness. My process without difliculty affords a cartridge-count of from 240 to 256 of the standard cartridge 1%" x 8" per 100 lbs., and an equivalent number in cartridges of other sizes, and the product has all the re uisite hardness and sturdiness and is the ull equivalent or better in explosive value than the prior product of relatively high density.

Entirely practical cartridges of even lower densitymay be produced by my process without undue complication. As com ared with the best of the prior products 0 the same class, therefore, my cartridge is characterized by its relatively low density, and the product consisting of a normally hard and mechanically strong black .powder cartridge of relatively low density is, so far as I am aware, new to the trade and represents-a major departure from and a material improvement over 'all prior available products.

As a further advantage, the end product of my process constitutes a material improvement over the-end product of th prior practice. The pellet formed in ace rdance with my invention takes the form of an integral be no limitation in stick of the required length and in this respect is -a material improvement over the stick made of a plurality of relatively small pellets bound together in an envelope as produced by the prior processes. A stick made In accordance with my invention also pos sesses a relatively greater uniformity of denand in this nor in any other respect is there any limitation as to the dimensions of the finished product. The invention affords a practicable method of making pellets of the highest quality of practically any required size. Further, the process lends itself readily to the use of an envelope scientifically water-proofed to reduce to a minimum the products tending to form noxious gases when the stick is exploded, this being of particular importance slty than the product of the prior methods,

where the blasting stick is used in mines or ally, although my normal andpreferred powder is somewhat faster than the pellet powder of prior practice, it is relatively slow burning in comparison with the normal expectation. This is due in part to the fact that the explosive takes the form of an integral body, the combustion being thereby restricted to a straight line progression through the entire mass, and this desirable action is aided by the fact that the envelope which in effect constitutes the mold, becomes an integral bonded part of the explosive itself as distinct from the more or less loose and independent wrapper of the prior practice between which and the explosive the combustion is permitted to progress as previously set forth.' It is evident that, in comparison with the prior practice, I have a form of speed increase and forms of speed retardation, which combination of influences is entirely different from prior art and, I suspect, are contributory in some way to the-great commercial success of my powder.

It will be understood that while it is en tirely practical to form a stick powder in accordance with my process using only black powder in the wheel cake stage, there is to this respect, and anular powder may be employed if found d e sirable. It is to be noted further that the invention is in no way restricted to any particular form or constituency of envelope, and the process in general may be varied to some extent without departure from the invention. Also,

while it is preferred to tamp the explosive directly in the envelope, for reasons advanced above, the invention is not limited to this procedure as certain advantages thereof may be realized by tamping the explosive in a separate mold or die as distinct from the prior practice of molding by simple pressure. It will be noted further that other bonding mediums or wetting agents than water may be used without departure from the invention, such for example as sodium silicate,

I shellac, starch paste, volatile liquids, or cementing mediums such as plaster of Paris. The term wheel cake is common in the industry to describe the product resultant from the incorporation of the various ingredients of the powder. It is the product in old practice which exists prior to pressing and corning. By wheel cake in this invention I mean broadly the incorporated product whether or not wheels are used for the incorporation. It will be clear and understood that the term molded black powder explosive as used throughout the specification and claims, is to be given its well known industrial and commercial meaning, and not to be restricted to a molded black powder of any particular color and /or chemical composition.

I claim:

1. The method of forming molded black powder explosives, which consists in formmg an envelope of required shape and dimensions, lightly tamping the powder in damp state into the envelope to form an explosive body of relatively low density conforming to the shape of the envelope, and drying the powder in and subsequently closing the envelope.

2. The method of forming molded black powder explosives, which consists in forming an envelope of required shape and dimensions, inserting a core in the envelope, lightly tamping the powder in damp state into the envelope and around the core to form an explosive body of relatively low density conforming to the shape of the envelope, subsequently withdrawing the core and drying the powder in the envelope, and thereafter sealing the envelope.

3. The method of forming molded black powder explosives, which consists in forming a moisture-proof envelope of required shape and dimensions, lightly tamping the powder in damp state into the envelope to form an explosive body of relatively low density conforming to the shape of the envelope, drying the powder in the envelope, and subsequently closing the envelo e to form a completely moisture-proof pac age.

4. The method of manufacturing molded black powder explosives, which consists in forming an envelope of required shape and dimensions, lightly tamping the powder with a moisture content of not less'than 1% by weight into the envelope to form a body of relatively low density conforming to the shape of the envelope, removing the moisture by a drying operation, and subsequently sealing the envelope.

5. The method of forming molded black powder explosives, which consists in forming an envelope of required shape and dimensions, tamping the powder in the wheel cake stage and with a moisture content of not less than 1% by weight into the envelope to form a body of relatively low density conforming to the shape of the envelope, and drying the powder in and subsequently sealing the envelope.

6. The method of manufacturing molded block powder explosives, which consists in forming a cylindrical open-ended envelope, lightly tamping the powder in damp state into the envelope to form a stick of relatively low density and of required length terminating short of the ends of the envelope, subjecting the package to a drying operation to remove at least a part of the moisture content of the powder, and subsequently folding over and sealing the projecting ends of the envelope.

7. The method of manufacturing molded black powder explosives, which consists in forming a cylindrical open-ended envelope, lightly tamping the powder in damp condition into the envelope to form a stick of required length, and of relatively low density subjecting the stick to a drying operation in the open-ended package, and subsequently closing the ends of the envelope."

8. The method of manufacturing molded black powder explosives, which. consists in forming a cylindrical open-ended envelope, inserting a longitudinal core in the envelope, lightly tamping the' powder in damp condition into the envelope to form a relatively low. density stick or' required length, with drawing the core to produce a longitudinal opening extending through the stick, subjecting the stick to a drying operation in the'open-ended package, and subsequently binding the entire mass into a firm, hard body.

10. The method of forming low density molded black powder explosives, which consists in forming an envelope of required shape and dimensions and constituting at least part of the ultimate container, assembling the inches in length, which consists in powder, plasticized with the envelope under light pressure, and drying the plastic mass in the envelope to thereby efiect crystallization of the dissolved ingredient binding the entire mass into a firm hard body.

11. The method of .forming low density black powder explosives, which consists in forming an envelope of required shape and dimensions and constituting at least part of the ultimate container, tamping the powder plasticized with a solvent medium into the envelope under light pressure, and subsequently drying the plastic mass in the envelope to thereby eflect crystallization of the dissolved ingredient binding the entire mass into a firm hard body.

12. The method of forming black powder explosives in the form of molded sticks of indeterminate length, which consists in tamping the powder plasticized with a solvent medium under light pressure into an envelope constituting at least a part of the ultimate container, and subsequently drying the plastic mass in the envelope to thereby efiect crystallization of the dissolved ingredient binding the entire mass into a firm hard body.

13. The method of forming monolithic black powder explosive sticks exceeding four forming an envelope of the required shape and dimensions and constituting at least part of the ultimate container, plasticized with a solvent medium into' the envelope, and subsequently drying the plastic mass in the envelope toefl'ect a crystallization of the dissolved ingredients knitting the mass into a hard mechanically strong monolithic stick.

14. The method which comprises assembling a blaekpowderexplosive plasticized with a solvent medium into an envelope under light pressure, and subsequently drying the plasticized mass and sealing the envelope.

15. The method which comprises, assembling a block powder explosive plasticized with a solvent medium into an envelope of cellulose material under light pressure, and subsequently drying the plastic mass in and sealing the envelope to form a mechanically strong, low density explosive.

16. The method of manufacturing molded black powder explosives, which consists in forming an envelope of required shape and dimenslons of a porous material, assembling the powder in moist condition in the envelope, subsequently drying the powder in the envelope, and thereafter treating the envelope to render it moisture proof.

17. The method of manufacturing molded black powder explosives, which consists in assembling the powder under pressure in a porous envelope, drying the powder in the envelope, and thereafter sealin and treating the envelope to a moisture proo g operation.

tam'ping the powder a solvent medium, in 18. The method of manufacturing molded black powder explosives, which consists in assembling the powder, together with a solvent plastlcizer in amount not less than 2% by weight of the explosive, under light pressure in amold constituting at least apart of the ultimate container, and subsequently drying the mass in the mold to form an explosive body rendered mechanically strong by crystalhzation of the dissolved ingredients.

19. The method of forming a molded black powder explosive, which consists in assembling powder from the wheel cake stage and plasticized with a solvent medium mto a mold under light pressure, and subsequently drying the plastic mass in the mold.

20.'The method of forming molded black powder explosives from wheel cake, which consists in partially dissolving at least one of the ingredients in the explosive composition by addition of a solvent medium massing the material in a mold under light pressure, and subsequently removing. at least the major portion of the solvent to efi'ect crystallization of the dissolved material with resultant binding efiect upon the entire mass.

21. A molded black powder explosive of relatively low density consisting of at least a part of the original mold containing, a loosely compressed, rigidly-bonded and highly aerated body of the explosive composition.

22. A molded low explosive of relatively low density comprising a. powder containing an inorganic salt, said explosive consisting of a loosely compressed, highly aerated body of the explosive composition bonded to rigidity by the cementing efl'ect of the inorganic salt ingredient that has been crystallized after formation of said body in the mold.

253. A highly aerated molded low explosive of relatively low density comprising a powder containing an inorganic salt, said explosive consisting at least in part of the .origlnal mold containing a loosely compressed mass of the powder bonded by the recrystallized inorganic salt ingredient.

'24. A molded low explosive comprising a formed body of the explosive composition containing an inorganic salt, said explosive having a compacted strength insuflicient to enable it to withstand removal from the mold in the unbonded state, and having an eventual sturdiness resulting fromthe bonding and cementing action of the inorganic salt ingredient that has been crystallized after formation of the body in the mold.

25. The method of producing a molded low explosive of relatively low density comprising a powder containing an inorganic salt, which consists in forming the explosive under compression too light to enable it to withstand removal from the mold without crumbling, and drying the explosive in the mold to rigidity the formed explosive by the bonding and cementing action of its inorganic salt ingredient.

26. The method of producing a molded low explosive of relatively low density comprising a powder containing an inorganic salt, which consists in loosely compressing the powder directly in the cartridge case as a mold to form a highly aerated mass, and subsequently drying the formed-explosive to 10 bond the mass to rigidity in the case by crystallization of the inorganic salt ingredient.

27. The method of producing a molded low explosive of relatively low density comprising a powder containing an inorganic 1 salt, which includes the steps of loosely compressing the powder in a mold consisting of at least a part of the cartridge case, and subsequently bonding the powder by crystallization of the inorganic salt ingredient.

28. The method of producing a molded low explosive of relatively low density comprising a powder containing an inorganic salt, which consists in loosely compressing the powder directly in the cartridge case as a mold to form a highly aerated mass, said ow'd'er having at least a portion of its solule inorganic salt content in solution, and subsequently drying the composition in the case to effect a bonding of the mass to rigidity lay crystallization of said soluble salt ingreient.

29. The method of producing a molded black powder explosive of relatively low 'density comprising a powder containing a Water-solnble in edient, which includes the steps of loose y compressing the powder in a mold consisting of at least a part of the cartridge case, and subsequently bonding the powder by crystallization ofjts water-soluble 40 ingredient. 1

JAMES E. SLUSSER.

CERTIFICATE OF CORRECTION.

Patent No. 1,913,344. June 6, 1933.

. JAMES E. SLUSSER.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 1, line 66, for "power" read "powder"; page 2, line 19, -for "so" read "to"; page 3, lines 61 to 64, strike out the words "As a further advantage, the end product of my process constitutes a material improvement over the end product of the prior practice." and insert the same before "The" in line 29; page 4, line 82, claim 6, for "block" read "black"; line 98, claim 7, strike out the comma after "length" and insert the same after "density" in the same line; page 5, line 46, claim 15, for "block" read "black"; and that the said Letters Patent should be read with these corrections therein that the same may conform to the record'of the case in the Patent Office.

Signed and sealed this 22nd day, of August; A. D. 1933.

M. J. Moore.

(Seal) Acting Commissioner of Patents.

CERTIFICATE OF CORRECTION.

Patent No. 1,913,344. June 6, 1933.

JAMES E. SLUSSER.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 1. line 66, for "power" read "powder"; page 2, line 19, for "so" read "to"; page 3, lines 61 to 64, strike out the words "As a further advantage, the end product of my process constitutes a material improvement -over the end product of the prior practice." and insert the same before "The" in line 29; page 4, line 82, claim 6, for "block" read "black"; line 98, claim 7, strike out the comma after "length" and insert the same after "density" in the same line; page 5, line 46, claim 15, for-"block" read "black"; and that the said Letters Patent should be read with these corrections therein that the same may conform to the record'of the case in the Patent Office.

Signed and sealed this 22nd day. of August,- A. D. 1933.

n. J. Mom.

. (Seal) Acting Commissioner of Patents. 

